package utils;

import com.mysql.cj.jdbc.MysqlDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBUtil {
    // 数据源
    private static DataSource dataSource = null;
    // 数据库连接串
    private static final String URL = "jdbc:mysql://127.0.0.1:3306/test001?characterEncoding=utf8" +
            "&allowPublicKeyRetrieval=true&useSSL=false";
    // 用户名
    private static final String USER = "root";
    // 密码
    private static final String PASSWORD = "Wtw771121";

    // 当类加载到JVM的时候，执行数据源的初始化
    static {
        MysqlDataSource mysqlDataSource = new MysqlDataSource();
        mysqlDataSource.setURL(URL);
        mysqlDataSource.setUser(USER);
        mysqlDataSource.setPassword(PASSWORD);
        dataSource = mysqlDataSource;
    }
    private DBUtil(){
        //防止别人实例化一个 DBUtil 对象
    }
    //获取数据库连接
    public static Connection getConnection() throws SQLException{
        return dataSource.getConnection();
    }
    //释放资源，关闭连接
    public static void close(ResultSet resultSet, PreparedStatement statement,Connection connection){
        if(resultSet!=null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(statement!=null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(connection!=null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

}
